Depending on a few factors (amount and type of junk, what city you are dealing with) you can estimate between $35-$55/CuYd. This includes dumpster and labor. USUALLY, the smaller the junk &/or city, the more expensive it will be to clean up.
There are cleanup services (eg JunkKing, JDog, TrashMan, etc). For really large jobs my students usually GC this part and save the $$$.
Let me know what else I can do to help you grow your business.
Greg
Greg Wilson
The REI Mentor